Line Relationships

What are parallel lines?

• Parallel lines are two lines in a plane that never meet.

• Parallel lines are two lines that are perpendicular to each other.

• Parallel lines are two lines that intersect at one point.

• Parallel lines are two lines that form a right angle.

How can you identify perpendicular lines?

• By checking if the slopes of the two lines are negative reciprocals of each other.

• By verifying if the lines have the same y-intercept

• By checking if the lines intersect at a right angle

• By comparing the lengths of the lines

What happens when two lines intersect?

• They intersect at a single point.

• They disappear

• They merge into one line

• They form a circle

Define line segments.

• Line segments are parts of a line that are bounded by two distinct end points.

• Line segments are only defined in three-dimensional space.

• Line segments are circles with infinite radius.

• Line segments are curved lines with no end points.

Do parallel lines ever meet?

• No

• Sometimes

• Only in certain conditions

• Yes

Can perpendicular lines be at an angle other than 90 degrees?

• No

• Rarely

• Sometimes

• Yes

How many points do intersecting lines have in common?

• 2

• 3

• 4

• 1

What is the difference between a line segment and a line?

• A line segment has no endpoints, whereas a line has two endpoints.

• A line segment has two endpoints, whereas a line extends infinitely in both directions.

• A line segment is curved, whereas a line is straight.

• A line segment is always parallel to a line, whereas a line can intersect with other lines.

Name a real-life example of parallel lines.

• Telephone wires

• City streets

• Railway tracks

• Intersecting lines

Explain how to determine if two lines are parallel.

• Check if the two lines intersect at a right angle.

• Check if the y-intercepts of the two lines are equal.

• Check if the slopes of the two lines are equal.

• Check if the two lines have the same length.